Introduction to JavaScript

Remember that methods are actions we can perform. JavaScript provides a number of string methods.

We call, or use, these methods by appending an instance with:

  • a period (the dot operator)
  • the name of the method
  • opening and closing parentheses

E.g. 'example string'.methodName().

Does that syntax look a little familiar? When we use console.log() we’re calling the .log() method on the console object. Let’s see console.log() and some real string methods in action!

console.log('hello'.toUpperCase()); // Prints 'HELLO' console.log('Hey'.startsWith('H')); // Prints true

Let’s look at each of the lines above:

  • On the first line, the .toUpperCase() method is called on the string instance 'hello'. The result is logged to the console. This method returns a string in all capital letters: 'HELLO'.
  • On the second line, the .startsWith() method is called on the string instance 'Hey'. This method also accepts the character 'H' as an input, or argument, between the parentheses. Since the string 'Hey' does start with the letter 'H', the method returns the boolean true.

You can find a list of built-in string methods in the JavaScript documentation. Developers use documentation as a reference tool. It describes JavaScript’s keywords, methods, and syntax.



Use the .toUpperCase() method to log the string 'Codecademy' to the console in all capital letters.


In the second console.log() statement in app.js, we have a string ' Remove whitespace ' which has spaces before and after the words 'Remove whitespace'.

If we browse the JavaScript string documentation, we find several built-in string methods that each accomplish a different goal. The one method that seems ideal for us is .trim().

Use the method to remove the whitespace at the beginning and end of the string in the second console.log() statement.

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